Abstract
<p> In this largely expository paper, we will present a list of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper E Subscript n"> <mml:semantics> <mml:msub> <mml:mi>E</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi>n</mml:mi> </mml:mrow> </mml:msub> <mml:annotation encoding="application/x-tex">E_{n}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> -operads and give complete, and in some cases new, proofs of the equivalences between these operads. </p>